This section provides background information related to the present disclosure which is not necessarily prior art.
Compressors may be used in heating and cooling systems and/or other working fluid circulation systems to compress and circulate a working fluid (e.g., refrigerant) through a circuit having a heat exchanger and an expansion device. Efficient and reliable operations of the compressor are desirable to ensure that the system in which the compressor is installed is capable of effectively and efficiently providing a cooling and/or heating effect. When the compressive capacity of the compressor is reduced (e.g., due to a capacity modulation event), such that the relative orbital movement between the orbiting scroll member and the non-orbiting scroll member is varied, the compressor may produce undesirable vibrations, sounds and noises.
Further, loss of efficiency and capacity can occur when high levels of heat transfer occur between undesirable regions in a compressor. For example, certain compressors (e.g., scroll compressors) may be hermetically or semi-hermetically sealed with a high-side pressure design that includes both a high-side pressure region and a low-side pressure region inside the compressor housing. In hermetically or semi-hermetically sealed motor compressors, the refrigerant gas, which enters the housing as vapor at the inlet on a low-side, passes into and is processed within the compression mechanism, where it forms a compressed, pressurized refrigerant gas that passes through a high-side discharge. When compressing the refrigerant (e.g., gas), work is required, thus generating heat. The processed discharge gas thus has significantly higher temperatures and pressures than the pre-processed suction refrigerant. The heat may undesirably be transmitted from the high-pressure discharge gas to the low-pressure side, thus increasing suction gas temperatures and undesirably reducing the suction gas density. By heating the refrigerant gas on the low-pressure suction or inlet side, the refrigerant gas increases its volume, thus a mass flow rate of refrigerant gas entering the compression mechanism is lower than a mass flow rate of gas that would otherwise enter the compression mechanism if the refrigerant gas was at a lower temperature.
This refrigerant heating thus causes a smaller amount of inlet refrigerant gas to be introduced into the compression mechanism, causing a loss of efficiency of the refrigerant cycle. If heat transfer from a high-pressure discharge side to the low-pressure suction/inlet side is reduced, this can improve compressor performance and discharge line temperatures. In other applications where the compressor is used in a heating mode, it may be desirable to reduce heat transfer of the high-pressure refrigerant gas to the low-side suction gas or to the compressor ambient. Reducing the heat transfer from the discharge gas can increase discharge temperatures and therefore improve the heating capacity provided by the system. In other applications it may be advantageous to increase heat transfer. This would allow certain compressor components to operate at a lower temperature.
It would be desirable to have high-strength, light-weight compressor components that advantageously control heat transfer within a compressor or reduce sound generation and vibration during compressor operation to improve compressor performance and efficiency.